Early microscopes offered sharp vision

March 4, 2011By Philip PB BallThis article courtesy of Nature News.

Images from the first microscopes were clearer than was once believed.

The first microscopes were a lot better than they are usually given credit for. That's the claim of microscopist Brian Ford, a specialist in the history and development of these instruments based at the University of Cambridge, UK.

Ford says it is often suggested that the microscopes used by seventeenth-century pioneers such as Robert Hooke and Antony van Leeuwenhoek gave a blurry view of biological structures such as cells and microorganisms. Hooke was the first to record cells, seen in thin slices of cork, while Leeuwenhoek described tiny 'animalcules', invisible to the naked eye, in rain water in 1676.

The implication is that these breakthroughs involved more than a little guesswork and invention. But Ford has looked again at the capabilities of some of Leeuwenhoek's microscopes, and says the results were "breathtaking", and comparable to those obtained with a modern light microscope. He describes his studies in Microscopy and Analysis1.

Inept modern reconstructions have given seventeenth-century instruments a bad name, says Ford. In contrast to the hazy images shown in some museums and television documentaries, the right lighting and focusing can produce micrographs of startling clarity using original microscopes or modern replicas ([slideshow 1 left]).

"Ford is the world's leading expert on the topic, and what he has to say here makes a good deal of sense," says Catherine Wilson, a historian of microscopy at the University of Aberdeen, UK.

Wonderful spectacle

Ford made some of these improvements when he was granted access to one of Leeuwenhoek's original microscopes owned by the Utrecht University Museum in the Netherlands. Leeuwenhoek, a linen merchant living in Delft, made his own instruments using a single lens — a tiny bead of glass mounted in a metal frame. These simple microscopes were harder to make and use than the more familiar two-lens compound microscope, but offered greater resolution.

Hooke popularized microscopy in his 1665 masterpiece Micrographia, which included stunning engravings of fleas, mites and the compound eyes of flies. The diarist Samuel Pepys judged it "the most ingenious book that I ever read in my life". Ford's findings show that Hooke was not, as some have suggested, embellishing his drawings from imagination, but should genuinely have been able to see such things as the tiny hairs on the flea's legs.

Even Hooke was temporarily foxed, however, when he was tasked with reproducing Leeuwenhoek's results. It took him more than a year before he could see these animalcules, whereupon he wrote: "I was very much surprised at this so wonderful a spectacle, having never seen any living creature comparable to these for smallness."

"The abilities of those pioneer microscopists were so much greater than has been recognized," says Ford. He attributes the misconception to a recent decline in the teaching of microscopy.